plunkerでshadertoy sandbox その29

概要

plunkerでshadertoyのglsl動かしてみた。
TUTORIAL、やってみる。

TUTORIAL 20

COLOR ADDITION AND SUBSTRACTION

float disk(vec2 r, vec2 center, float radius) {
	float distanceFromCenter = length(r - center);
	float outsideOfDisk = smoothstep(radius - 0.005, radius + 0.005, distanceFromCenter);
	float insideOfDisk = 1.0 - outsideOfDisk;
	return insideOfDisk;
}
void mainImage(out vec4 fragColor, in vec2 fragCoord) {
	vec2 p = vec2(fragCoord.xy / iResolution.xy);
	vec2 r = 2.0 * vec2(fragCoord.xy - 0.5 * iResolution.xy) / iResolution.y;
	float xMax = iResolution.x / iResolution.y;
	vec3 black = vec3(0.0);
	vec3 white = vec3(1.0);
	vec3 gray = vec3(0.3);
	vec3 col1 = vec3(0.216, 0.471, 0.698);
	vec3 col2 = vec3(1.00, 0.329, 0.298);
	vec3 col3 = vec3(0.867, 0.910, 0.247);
	vec3 ret;
	float d;
	if (p.x < 1. / 3.)
	{
		ret = gray;
		d = disk(r, vec2(-1.1, 0.3), 0.4);
		ret = mix(ret, col1, d);
		d = disk(r, vec2(-1.3, 0.0), 0.4);
		ret = mix(ret, col2, d);
		d = disk(r, vec2(-1.05, -0.3), 0.4);
		ret = mix(ret, col3, d);
	}
	else if (p.x < 2. / 3.)
	{
		ret = black;
		ret += disk(r, vec2(0.1, 0.3), 0.4) * col1;
		ret += disk(r, vec2(-.1, 0.0), 0.4) * col2;
		ret += disk(r, vec2(.15, -0.3), 0.4) * col3;
	}
	else if (p.x < 3. / 3.)
	{
		ret = white;
		ret -= disk(r, vec2(1.1, 0.3), 0.4) * col1;
		ret -= disk(r, vec2(1.05, 0.0), 0.4) * col2;
		ret -= disk(r, vec2(1.35, -0.25), 0.4) * col3;
	}
	vec3 pixel = ret;
	fragColor = vec4(pixel, 1.0);
}

写真

成果物

以上。